VACCINE

Mpox (monkeypox) Imvamune® 
(live-attenuated, non-replicating)

SHOULD TITRES BE CHECKED?

Not applicable. In the context of an active mpox outbreak, vaccination using Imvamune® should be offered to individuals/groups considered at high-risk of mpox.

BEFORE INITIATION OF IMMUNE SUPPRESSION

Note: Infectious Disease consultation is suggested for pediatric patients under age 18. The IMVAMUNE® formulation is live-attenuated but non-replicating, so this is a discretionary recommendation for immunocompromised individuals based on exposure. The freeze-dried and frozen liquid formulations are contraindicated.

Post-exposure vaccination using a single dose of Imvamune® may be offered to individuals with high-risk exposures to a probable or confirmed case of mpox or within a setting where transmission is happening. Post-exposure vaccination should be offered as soon as possible, ideally within 4 days (but up to 14 days) of last exposure. A second dose may be offered after 28 days from the first dose if an assessment indicates an ongoing risk of exposure or if the individual is in a high-risk group for whom pre-exposure vaccination is recommended.

During the 2022 outbreak, the following individuals/groups were considered for pre-exposure vaccination with Imvamune®:
  • Men who have sex with men (MSM)—and individuals who have sex with MSM—and who meet at least one of the following criteria:
    • Having two or more sexual partners or being in a relationship where at least one of the partners has other sexual partners
    • Having had a confirmed sexually transmitted infection acquired in the last year
    • Engaging in sexual contact in sex-on-premises venues
  • Individuals who self-identify as sex workers regardless of self-identified sex/gender
  • Staff or volunteers in sex-on-premises venues where workers may have contact with fomites potentially contaminated with monkeypox virus without the use of personal protective equipment

WHAT TO DO IF ALREADY IMMUNOSUPPRESSED
(ON ANTI-TNF OR IMMUNOMODULATOR)

Individuals receiving pre-exposure vaccination should be offered Imvamune® as a two-dose primary series, with at least 28 days between first and second 0.5 mL sub-cutaneous doses. Individuals considered moderately to severely immunocompromised and eligible for pre-exposure vaccination should be prioritized to receive two doses of Imvamune® administered at the authorized interval (28 days between doses).